Pipe coating method and machine



I July 1-7, 1934.

w. A. KRANER PIPE COATING METHOD AND MACHINE Filed June 14, 1933 6Sheets-Sheet l W Mw 4 A Z r M wf w JH mHHLH July 17, 1934. w. A. KRANERPIPE COATING METHOD AND MACHINE Filed June 14, 1953 6 Sheets-Sheet 2INVENTOR. Warren ,4. k ra/v'er ATTORNEYS.

July-l7, 1934. w. A. KRANER PIPE COATING METHOD AND MACHINE Filed June14, 1933 6 Sheets-Sheet 3 INVENTOR. VZ a/"rer/ A. {fa/7e! ATTORNEYS.

Judy 17, 1934. w. A. KRANER PIP E COATING METHOD AND MACHINE Filed June14, 1953 6 Sheets-Sheet 4 INVEN TOR. H arren 4. M'afler m Ii F F W swig.N W34 w. A. KRANER PIPE COATING METHOD AND MACHINE Filed June 14, 1933 6Sheets-Sheet 5 F'IE E IN VEN TOR. Warren 4. Kramer ATTORNEYS.

W. A. KRANER PIPE COATING METHOD AND MACHINE Filed June 14, 1933 6Sheets$heet 6 INVENTOR. Warren ,4. Era/76f ATTORNEYS.

m chine incorporating Patented July 17, 1934 PIPE COATING METHOD ANDMAQJHINE Warren A. Kroner, San Francisco, Calif" assiznor to CementWrapped Pipe Company,

PATENT OFFICE Ltd San Francisco, Calif" a corporation of ArizonaApplication June 14, 1938, Serial No. 675,659 24 Claims. (Cl. 2M0) Thisinvention relates generally to methods of applying protective coatingslike hydraulic concrete to metal piping or and to machines useful formethods.

It isa general cylindrical forms,

carrying out such.

object of the invention to generally improve methods and machines of theabove character, to make possible the manulecture of a uniform coatingor armor or high protective value at relatively low cost.

A further object of ride an improved method oi ter which will makepossible the invention is'to pro the above charac= a dense and hardprotective coating which will be relatively tree or objectionable voids.

Another object or the invention is to provide a machine for applyingplastic material like hydraulic concrete or .to a pipe or cylindricalform.

hydraulic concrete mortar which will operate a relatively high speed,and which will apply a foraminous reinforcement in proper embeddedposition simultaneously with plastic material.

application of the Further objects or the invention will'appear thefollowing description irlwhich the preferred embodiment of the inventionhas set forth in detail in conjunction with the eo= companying drawings.

Figure l is end view,

illustrating a rue the present invention.

2 is a view similar to Fig. 1, out looking toward the opposite end of.the machine.

Fig. 3 is a side elevational view oi a portion of the machine shown inillustrating particularly means the pipe being coated.

side elevational detail, partly in illustrating the centers tor roupperside of Fig. i is a cross section,

Figs. 1 and 2, and

i or vibrating the tatacly supporting small pipe or other term he= inscoated.

Fig. 5 is a plan view, or the reinforcing material.

Fig. 8 is a plan view,

illustrating the wrapping illustrating the complete machine in operationfor the coating cl 2. length of pipe.

Fig. '7 is a plan view,

in cross section, illustrating a portion or the carriage which supportscertain operating parts of Fig. 8 is a side elevational view.

the machine. partly in cross section, illustrating means for supportingthe pipe or other form to be rotated, and to be coated.

Fig. 9 is a side section, of the continuation Fig. 8.

elevatlonal view, partly in cross of the left side of 'Referrlng firstto the shown in Fig. 8, the machine consistsgenerally plastic Fig. 10 isa side elevational detail, incross section, showing the guide structureover which the plastic material passes in its advance upon the pipe orother form being coated.

Fig. 11 is a cross sectional detail taken along 60 the line ll-ll ofFig. 10.

Fig. 12 is an enlarged detail, showing the manner in which thetoraminous reinforcement becomes embedded in the layer of plastic material, thru the eflects of tension and vibration. M

Fig. 12A is a cross section taken along the line 12Al2li of Fig. 12.

Fig. 13 is a cross sectional detail, illustrating periorating meanswhich can be utilized where paper is employed as an outer surfacing.

The method incorporating in the invention can be best understood after adetailed description of the machine illustrated in the drawings.

general layout in plan,

of a pair of structures it and it for supporting a pipe 12 or othercylindrical term, for axial rotation. Arranged along one side or thepipe 12 there is a carriage 13 adapted to operate along a traclr is. Thecarriage 13 supports various mechanical elements which serve'to applythe material to the pipe 12, and may also carry a mixing apparatus itfor supplying plastic material in proper condition. It he explained thatwhile the machine is in op eration with the pipe 12 being continuouslyro tatcd in one direction, the carriage is moved continuously lengthwiseor the pipe, and the plastic material is applied spirally orhelicoiclally,

as illustrated.

Referring now to Figs. land 2, the carriage it consists of a suitableirarne llwhichcan he formed of structural steel members, as shown. Thelower portion of this frame carries wheels 18 for operating upon thetrack i l. Carried by the frame 17, thru certain elements to hepresently described, there is a guide structure 19. It is over thisguide structure that the plastic material is conveyed, during itsapplicstion to the pipe 12.

The particular details shown for the guide structure 19 can be explainedby reference to Figs. 10 and 11. The principal part of this guidestructure is formedv by a channel 21 having its flat back sideuppermost. In order to operativcly support channel 21, a plate 23underlies its intermediate portion, and the ends of this plate aresecured to the depending side channel flanges 24. A stirrup 26 underliesplate 23 and these parts are pivotally connected to- 1 i of bolts 31which can be engaged in any one of several apertures in the uprightmembers 30.

Yoke 28 is in turn adjustably mounted on ele- It is.

ments 98 as will be presently explained. evident from what has beenexplained that the support for the channel 21 permits universal movementof this channel with respect to the pipe being coated. In other wordsthis channel can be swung about a generally upright axis at variousangles with respect to the axis of rotation of the pipe, or it can betilted at various angles with respect-to the horizontal,

In order to provide means for continuously feeding a layer of plasticmaterial upon the upper surface of the channel 21, I provide a hopper33, which can be made of sheet metal plates, welded together. 21, and ispreferably positioned substantially co-axial with the axis of pivot pin27, so that varying amounts of material within the hopper hassubstantially no effect upon counterbalancing of the channel. Forreasons which will be presently apparent it is desirable to retainhopper 33 in its operating position by a hinge connection, so that itcan be unlocked and swung to one side. Thus one sideof the hopper hasbeen shown connected to one side of the channel 21 by hinge structure34. The other side of the hopper is adapted to be retained in operatingposition by releasable locking means which may be formed as follows:-Arod 36 base. pivotal connection 37 with one side of the channel 21. Acollar 38 is slidably positioned upon rod 36 and is urged toward thepivotal connection 37 by compression spring 39. Mounted upon thecorresponding side of hopper 33, there is a bracket 41, having a lowerflange 42 which is slotted to receive rod 36. Upon swinging rod 36outwardly and downwardly, collar 38 is freed with respect to flange 42,to permit the hopper to be swung to one side about the axis of hingestructure 34. When the hopper is returned to its normal position, rod 36can be swung upwardly to again engage collar 38 above the slotted flange42. In this connection it will be noted that the surfaces of collar 38are so formed, as to permit its automatic engagement with the uppersurface of flange 42, when the rod 36 is swung upwardly.

Certain parts associated with the hopper 33 serve to determine thethickness of the coating applied to the pipe. Therefore it isdesirableto have this hopper occupy a predetermined position with respect to thechannel 21 when it is in its operating position. For this reason spacerelements 44 have been shown interposed between the lower side edges ofthe hopper 33, and the side edge portions of channel 21. The hopperrests upon these spacer bars or elements, when it is in normal.operating position as shown in Fig. 11. Plastic material fed into hopper33 is fed forwardly over channel 21, towards the pipe to be coated. Asmooth'surface for the upper side of the channel can be assured by asheet metal surfacing 46. In order to prevent any forward hopper wall51.

This hopper overlies the channel the hopper.

flow of plastic material in the reverse directerial from the hopper in adirection towards the pipe, a plate 49 is removably secured to the Thelower portion of plate 49 is provided with a forwardly curved lipportion 52, which overlies the upper surfacing 46 of the channel 21.With this arrangement it is evident that the thickness of spacerelements 44 determines the thickness of the coating applied.

Inorder to secure a uniform and continuous flow of plastic hydraulicPortland cement or Portland cement mortar from hopper 33, below the lipportion 52, I provide means which serves to subject certain parts torapid and continuous vibration. Thus mounted upon the forward wall 51 ofhopper 33, by way of a bracket 56, there is a pneumatic hammer 57. Theoperating plunger 58 of this hammer bears upon a bar 59, which in turnrests upon lip portion 52. Since lip 52 is somewhat resilient and hasits side edges free with respect ,to the hopper, it is vibrated in avertical direction to insure a smooth continuous flow of plasticmaterial from In addition the main part of the hopper 33;and-particularly the rear wall 47, is subjected to continuous vibrationby means of an additional pneumatic hammer 61.

During its movement from the hopper to the pipe, the layer of plasticmaterial fed from the hopper is conveyed along by a strip of suitablematerial, such as a strip 62of wire screening, or like foraminous metalreinforcement. As is evident from Fig. 10, this stripof reinforcementpasses beneath the lower edge of gate 48 and is therefore substantiallyflat upon the upper surfacing 46 of channel 21 as it passes beneath thehopper toward the pipe. The mounting for the reel supplying thisreinforcement will be explained in the subsequent part of the presentdetailed description. I-Iowever, at this point it may be explained thatthe reinforcement is preferably placed under tension, and is flattenedbefore it is passed beneath hopper 33. Thus, referring to Fig. 10, thereinforcing strip 62 is shown passed beneath a roller 63 fixed to theside brackets 64. From roller 63 the reinf0rcement passes over roller 66and fixed roller 6'7, before it passes beneath the hopper 33. Rollers 66and 67 are carried by the side brackets 68, and roller 66 is adjustableby hand screws 69. The manipulation of -screws 69 makes it possible tokeep the reinforcing strip from becoming narrow; that is, it enables anoperator to keep one side of the strip from advancing ahead of the otherside. In the event the reinforcement tends to advance too rapidly on oneside, the screw 69 on that side is turned down to force that end of theroller66 against roller 67, thus causing sufficient friction on roller67 to allow the retarded side of the reinforcement to 4 catch up.

an extension plate 71. The upper surface of this plate is substantiallycoplanar with the upper surfacing 46 of channel 21, and interposedbetween the forward end edgeof channel 21, and adjacent edge of plate71. there is a lateral slot 72. Plate '71 is fixed to side structuralmembers 73, which in turn are secured to the side flanges 2 of channel21. For! reasons which will be subsequently explained. plate 711spreferably vibrated rapidly in a vertical direction. For this purpose Ihave shown pneumatic hammer '74 mounted upon structural members 13.beneath the plate 71. The operating plunger 76 for this hammer engages across-bar '17, which in turn engages the under side of plate 71. Inorder to confine the layer of plastic material during its movement fromhopper 33 to plate 71, side guide strips 75 are mounted upon the edgeportions of channel 21 (Fig. 19).

During operation of the machine it is desirable to have plate '11yieldably urged upwardly against the lower side of the pipe, but undervarying conditions of operation, it is desirable to adjust the amount ofthis force- To enable such adjustments there is shown a cross-bar '79secured to structural members "13, and upon which variouscounterbalancing weights 79 can be disposed. An increased amount ofweight applied to cross-bar 78, obviously tends to reduce the forcenormally urging plate 11 upwardly against the lower side of the pipe.

Simultaneously with the application of plastic material and iorarninousreinforcement to the pipe, it is desirable to apply an outer surfacingmaterial. Good results have been secured by utilizing ordinary cottoncheesecloth, although paper can be employed if desired.

Thus referring to Fig. 19, there is shown a strip S1 of cheesecloth,which is supplied from a reel to be presently described. As this stripcomes from the supply reel, it is passed between a of parallel bars 82,to remove wrinkles and the iike. From bars 82, the clothstrip passesover a guide plate 83, which is carried upon the under side of channel21. Upon leaving the forward end of guide plate 83, the cloth strip ispassed over a roller 8 1, and from thence is passed upwardly thru slot72, to the upper side of plate 71. 1

1n the event paper is employed in place of cloth, it is desirable toprovide the paper with erfo ations to permit extrusion of water and tofacilitate subsequent curing. This can be accomplished by the attachmentillustrated in detail in Fig. 13. In this case. in place of passing thepaper between the bars 82. the paper is passed between a pair ofperforating rolls 86 and 87, which are carried by the rear end ofchannel 21. After being perforated, the paper passes over the guideplate 83, and eventually thru the slot 72 upon the upper side of plate71, as has been previously described for application of cloth surfacing.

Referring now to Fig. 1, it. will be noted that the foraminous metalreinforcement 62 is supplied from a reel 91, and the surfacing strip 81supplied from a reel 92. rotatably carried by brackets 93 and 94, whichin turn are carried by the upright structural members 96 of a sub-frame97- The horizontal structural elements 98 of sub-frame 9'? are disposedupon the lower platform 99 of the carriage frame 17. lteferring to Fig.11 it will be noted that yoke 28 is mounted upon the structural elements98, and that the sub-frame as a whole at this point ispivotally'connected to the pressure to the ends lower platform 99, bymeans of pivot pin 101. This pivotal connection permits generaladjustment of the sub-frame 97 about a vertical axis alined with theaxis of pivot pins 29, so as to enable a general alinement of the reels91 and 92 with respect to the entire guide structure 19. When thesub-frame 97 is adjusted to a proper position with respect to guidestructure 19, it is clamped in such adjusted position to the lowerplatform 99. For this purpose Fig. 7 shows a portion of the platform-99provided with a series of holes 103, which can receive clamping bolts.

During certain times, as for example in set- I ting the machine up foroperation; it is desirable to raise the outer end of guide structure 19upon a relatively fixed rest. Thus referring to Fig. 10, a rod 106 hasbeen shown excentrically pivoted to the upright members 96 of thesubframe 97. When this rod is swung upwardly it serves as a rest for theguide structure 19, as shown in Fig. 1. However when swung downwardly asshown in Fig. 10, it is disengaged with respect to the guide structure.

Referring to Fig. 1, it will be noted that the sides of channel 21, forthat portion of the channel lying between the uprights 96, are pro videdwith side rollers 101. These rollers serve to engage the inner opposedfaces of uprights 96, thereby limiting lateral movements of the channel,but permitting movements in a vertical direction with a minimum ofresistance.

A suitable arrangement for supporting large sized pipes to be coated isshown in Figs. 8 and 9. In this case a rotatable shaft 111 is carried bythe journals 112. suitably supported upon a base 113, which can beformed of a pair-"of rails. An expansible chuck 114 is fixed to shaft111 and serves to engage one end portion of the pipe 12. Arranged belowshaft 111, there is a countershaft The journals are in turn 115, adaptedto be driven by a motor 116 (Fig.

2) thru the change speed gear sets 11'? and 118, and the gear box 119.Pinion 121 is splined to shaft 115, and engages with a gear 122 fixed toshaft 111. To secure a different drive ratio, another pinion 123 islikewise splined to a shaft 115, and is adapted to engage a gear 124fixed to shaft 111. A suitable clutch 126 is interposed between theconnection from gear box 119 and shaft 115, to disrupt the driveconnection if desired.

The other end of the pipe 12 is engaged by an expansible chuck 128 whichin turn is rotatably secured to one end of a longitudinally slidableplunger 129. Plunger 129 is splined in the standard 131 and extendsthrough a stationary, hydraulic cylinder 132. A piston 133 operateswithin cylinder 132, and is fixed to the plunger 129. The parts justdescribed are supported upon a carriage 134, which is provided withwheels to operate upon the rails 113. Hydraulic pressure for operatingpiston 133 can be provided by a gear pump 136, driven by an electricmotor 137. I The hydraulic circuits connected to In order to affordmeans for quickly shifting carriage 134 longitudinally of the rails 113,I have shown a hydraulic or pneumatic cylinder 139, which is mountedupon the carriage 1134. Within the cylinder 139 there -.is a piston 141,connected to a piston rod 142. The cutcr cnd of piston rod 142 isanchored to an abutment 143, which is fixed to the rails 113. Byselectively introducing compressed air or liquid under of cylinder 139,the carriage 13 to its initial position.

134 can be moved along the'rails 113 to a desired position.

Fig. 4 illustrates an arrangement which can be employed when relativelysmall pipe is to be coated. In this case, in place of utilizingexpansible chucks engaging the ends of the pipe,

'the ends of the small pipe 146 are engaged by '14 at a speed bearing adefinite ratio to the speed of rotation of the parts. Thus a driveconnection tothe carriage is illustrated as follows:-Mounted upon theshaft 111 (Figs. 2 and 8) there isan expansible pulley 151. Mountedwithin the base 113 there is a rotatable shaft 152, carrying a pulley153. Pulleys 151 and 153 are connected by cables 154, which aremaintained tensioned by the idler pulley 156. Ex-

tending laterally of the track 14, there is a shaft 157, which is drivenfrom shaft 152 thru bevel gears 158. The end of shaft 157 whichterminates between the rails of track 14 (Fig. 2) carries a sprocket159, which is engaged by one end of an endless chain 161. Chain 161extends the full length of movement of carriage 13, and its other endengages the idler sprocket 162. Underlying the main carriage 13 (Fig. 1)there is a guide channel 163 thru which the upper run of the chainextends. Mounted upon the carriage 13 there is a suitable mechanism,under the control of the operator whereby the upper run of the chain canbe locked to the carriage, to drive the same. This locking means neednot be described in detail, as its construction will be apparent tothose skilled in the art.

After coating 9. section of pipe it is desirable to provide means forquickly returning carriage For this purpose I have shown a suitablemotor 171 (Fig. 7), which may operate from pneumatic pressure, and whichis adapted to drive the axle for one or more of the wheels of thecarriage, thru a chain connection 172, and clutch 173.

- coating operation, it is desirable to provide a mixing apparatus 16upon the carriage 13. The details of this mixing apparatus need not bedescribed, as many apparatuses of this character which will operatesatisfactorily are known upon the market. However it may be, explainedthat the hydraulic plastic mix prepared in this apparatus is dischargedthru a launder 178. to the hopper 33 as shown in Fig. 1. The gate 179,controlling the discharge of the plastic mix, can be operated to eifectopening and closing of the same, by the hydraulic or pneumatic cylinder181.

To secure a denser final coating it has beenfound desirable to applyvibration to the plastic coating along the upper side of the pipe. Forthis purpose I have shown a plate 186 (Fig. 3) supported by a bracket187, through the parallel motion links 188- and 189. A pneumaticvibrator 191 is attached to plate 186 to rapidly vibrate the same inavertical direction. During operation of the machine plate 186 rides uponthe coating immediately after its application, whereby :all of theplastic material applied passes beneath the same and thereby issubjected to vibration. When the machine is not operating, plate 186 canbe retained in an elevated position by latch 192, which is adapted toengage pin 193.

Operation of my machine is as follows:The machine is initially set upand adjusted to secure the thickness of coating desired, and to insureproper operation consistent with diameter of the pipe being coated. Inthis connection the subfra me 97 must be so adjusted that the angularityof guide structure 19 with respect to the axis of the pipe, will applythe material to the pipe with the proper pitch. The metal reinforcing 62and the cloth strip 81 are properly threaded ,with respect to the guidestructure 19, and the ends of these strips are then secured to that endof the pipe 12 at which the coating is to be started. A proper plasticmix prepared-in the mixing apparatus 16, and a charge of this mix isthen introduced into the hopper 33. The various pneumatic hammers andvibrators are now put into operation, and rotation of the pipe iscommenced, with simultaneous synchronized movement of the carriage 13longitudinally of the pipe. As the strip of foraminous reinforcementprogresses beneath hopper 33, a layer of the plastic mix is applied tothe same, for substantially the full width of the reinforcement, andthis layer of plastic material is then conveyed together with thereinforcement. In other words the reinforcing strip serves as aconveying medium for the layer of plastic material'fed from the hopper.As the reinforcement progresses over plate 71, the cloth strip 81 isapplied to the under side of the same, to be simultaneously wrapped uponthe pipe. As has been previously explained the foraminous reinforcementis under tension as it is applied to the pipe. The rapid verticalvibration of plate 71 serves to repeatedly pound the layer of plasticmaterial and likewise the accompanying reinforcement, against the lowerside of the pipe, adjacent to or at the region of initial contact withthe pipe surface. The effect of such combined tension and vibration uponthe reinforcement, causes the reinforcement. to embed itself to anintermediate depth in the layer of plastic material, This can best beexplained by reference to Figs. 12 and 12A. As illustrated in thesefigures the foraminous reinforcement 62 is gradually embedding itselfinto the layer 9 of plastic material, as the reinforcement progressesalong the upper side of plate 71. It has been found that with a Portlandcement mix containing sand, and possibly somewhat coarser aggregatematerial such as fine gravel, the metal screening forming thereinforcing strip will embed itself to an intermediate depth, but willnot become embedded sufficiently for it to contact with the outersurface of the pipe. At this point it may be explained that thereinforcement, in order to be effective, must be embedded to anintermediate depth in the layer of plastic material applied to the pipe.If it is applied directly to the outer surface of the pipe, then it willnot properly perform its desired reinforcing function. wise if it ispermitted to occupy a position adjacent the outer surface of the plasticlayer, and then it will not properly reinforce thecoating, and it willbe exposed to corrosion.

Likeill In further explanation of the manner in which memes thereinforcement is embedded in the plastic material, as explained withrespect to Figs. 12 and 12A, it should be noted that embedding movementof the foraminous reinforcement necessarily is accompanied by extrusionof the plastic material thru the apertures in the reinforcement.Ordinarily extruded plastic material would not form a smooth outer layerportion over the reinforcement, unless troweled. However application ofthe cloth strip 81 over the plate 71 together with vibration makes atroweling operation unnecessary. Thus it will be noted that while theplastic material is extruding thru the foraminous reinforcement, it isbeing confined by the cloth strip, which is under a certain degree oftension, and such coniinernent of the plastic material, accompanied bythe vibration to which the plastic material is being subjected by plate'31, effectively compacts the extruded plastic material to form a denseouter layer portion. Use of the cloth strip also makes possibleapplication of the coating material at relatively high speed, becausethe cloth prevents throwing off of the plastic material by centrifugalforce.

Plate ii also assists in forming an effective junction betweensuccessive convolutions of the plastic material as this material issupplied. Thus referring to Figs. 5 and 12A, it will be seen that thepitch at'which the reinforcement is applied together with the plasticmaterial, is such as to cause adjacent edges of the reinforcement tooverlap. Since the layer of plastic material is appliedto substantiallythe full width of the reinforcement, there is also an overlap withrespect to the adjacent edges of the plastic material applied. Plate ll,due to the rapid vibration to which. it is subjected, effec tivelypounds down this overlap, so that the resulting coating is ofsubstantially uniform thick ness. Not only does this overlap provide arelatively strong junction between successive convolutions but likewisethese junctions are rendered relatively free of voids, due to thesurplus plastic material utilized in these regions and the pounding downof the same. it will also be noted from Figs. 5 and 12s. that as thecloth 81 is applied, it is offset so that one edge portion sic of thesame extends beyond the adjacent edge of the reinforcement and of theplastic material. This serves to form an overlap between adiacentconvolutions of the cloth strip. Likewise the offset manner in which thecloth is applied leaves exposed a certain amount of the plasticmaterial, to form a proper junction with the next convolution. By aninspection of Fig. 12A, the effectiveness of the bond secured betweensuccessive convolutions will be appreciated.

The upper vibrating plate 186 has been found highly effective inremoving trapped air bubbles from the plastic material. It is desirableto largely remove such trapped air bubbles, in order to densify thecoating, so that after the coating material sets and hardens, it affordsutmost strength and is less pervious to moisture and chemicals. Thelower vibrating plate '11 is not effective in removing air bubbles, forthe reason that air bubbles tend to rise upwardly at this point towardsthe outer surface of the pipe. However when vibration is applied to theupper side of the pipe byplate 186, the air bubbles rise from the outersurface of the pipe towards the outer surface of the coating.

During a coating operation considerable water is squeezed from thehydraulic plastic material, due to the pounding to which it is subjectedand to the tension of the cloth surfacing. Although it is desirable toresort to hydraulic curing to insure proper strength and hardness,squeezing out of excess water at this time aids insecuring a highlydensified coating.

After the machine has operated to apply the coating to one section ofthe pipe, further operation is discontinued, and the metal and clothstrips are out. This coated section is now removed from the machine anda new pipe ap-' plied .in position to be coated. The carriage 13 isreturned to the other end of the pipe and the operations described aboveare repeated. After the concrete has set, the ends of the pipe can betrimmed. in any desired manner.

The present specification is a continuation in part of subject matterdisclosed in my copending applications Serial Nos. 494,822 and 537,009,filed November 10, 1930 and May 13, 1931, respectively.

I claim:

l. in a method of applying a layer of hydraulic plastic material to aform, the steps of continuously applying a layer of the plastic materialupon a strip of foraminous metal reinforcement, wrapping the stripspirally about the form, and applying vibration and tension to thereinforcement as it is applied to cause it to embed itself to anintermediate depth in the layer of plastic material.

2. In a method of applying a layer of hydraulic plastic material to aform,, the steps of continuously applying a layer of the plasticmaterial upon a strip of foraminous metal re-- inforcement, wrapping thestrip spirally about the form, simultaneously wrapping a strip ofcovering material upon the form upon top of the plastic material and theforaminous reinforcement, and applying vibration and tension to thereinforcement as it is applied to cause it to embed itself to anintermediate depth in the layer or" plastic material.

3. in a method of applying a layer of hydraulic plastic material to aform, rotating the form about its axis, continuously supplying a layerof theplastic materialupon a strip of foraminous metal reinforcement.wrapping the strip spirally about the form with the strip together withthe plastic material advancing towards the lower side of the form,simultaneously applying a strip of outer surfacing material upon theunder side of the metal reinforcement as this reinforcement is advancedtoward the form, and then applying vibration and tension to thereinforcement as it is applied to the form to cause it to embed itselfto an intermediate depth in the layer of plastic material.

4.111 a method of applying a layer of hydraulic plastic material to aform, the steps of rotating the form about its axis, continuouslysupplying a layer of the plastic material upon a strip of foraminousmetal reinforcement.

wrapping the strip together with the layer ofplastic material spirallyupon the form, with the reinforcement being advanced toward the underside of the form, simultaneously applying a strip of surfacing materialspirally about the form, with the strip of surfacing material beingadvanced upon the form upon the under side of the foraminoiisreinforcement as this reinforcement is being applied to the form,applying tension to the foraminous reinforcement and applying vibrationto the reinforcement and theplastic material as it is being applied tothe form, whereby the reinforcement is caused to embed itself to anintermediate depth in the layer of plastic material, and whereby thatportion of the plastic which material is caused to assume a positionoverlapping the foraminous reinforcement is made relatively compact.

5. In a methodof applying a layer of hydraulic plastic material to aform, the steps 'of rotating the form about its axis, advancing a layerof the plastic material to the underside of the form whereby the layeris wrapped spirally upon the form, rapidly pounding the plastic materialnear the region where it is being applied to the under side of the form,and then rapidly pounding the applied layer adjacent the upper side ofthe form, thereby causing removal of air bubbles.

6. In a method of applying a layer of hydraulic plastic material to aform, the steps of rotating the form about its axis, wrapping a strip offoraminous reinforcement spirallyabout the form, causing the metalreinforcement to be applied to the form together with a layer of theplastic material extending for substantially the full width of thereinforcing strip, causing a substantial overlap between adjacent edgeportions of the reinforcing strip and of the plastic material appliedtogether with the same, upon the form, and rapidly pounding the regionsofsaid overlap to produce a resultant coating of substantially uniformthickness.

'7. In a method of applying a layer of hydraulic plastic material to aform, the steps of rotating the form about its axis, advancing towardsthe lower side of the form, a strip of foraminous reinforcement, a stripof surfacing material underlying the foraminous reinforcement, and alayer .of the plastic material upon the foraminous reinforcement andextending for substantially the entire width of the reinforcement,causing the foraminous reinforcement, together with a strip ofsurfacingmaterial, and the plastic material, to be wrapped spirally about theform, with adjacent edges of the foraminous reinforcement overlapping,causing the strip of surfacing material to be likewise applied withoverlapping edge portions adjacent the region of the overlap between theedge portions of the foraminous reinforcement, applying tension to. thereinforcement as it is applied upon the form, then applying rapidpounding to the plastic material applied to the form before hardening ofthe same, to reduce the thickness of. the coating along the region ofthe overlap and to cause the reinforcement to embed itself to anintermediate depth in the layer of plastic material.

8. In amethod of applying a layer of hydraulic plastic 'material to aform, the steps of continuously rotating the form, continuouslyadvancing a strip of material to the form whereby the strip is wrappedspirally about the form, and continuously squeezing excess water fromthe plastic material as it is applied.

9. In a method of coating a pipe or like form, advancing superposedstrips of foraminous reinforcement and surfacing material toward theform, with the surfacing outermost, causing these strips to be wrappedspirally upon the form, applying a layer of plastic material upon theinner side of the reinforceing strip, and then causing the reinforcingstrip to embed itself into the layer of plastic material whilesimultaneously compacting that portion bf the plastic material which isextruded thru the reinforcing strip.

10. In a machine of the character described; means for supporting androtating a pipe or other form to be coated, a hopper adapted to receivea mass of hydraulic plastic material and having a lowerdischargeopening, means for guiding a foraminous strip beneath said opening,whereby plastic concrete fed thru said opening is deposited upon saidstrip, means for applying tension to the foraminous strip as this striptogether with the plastic material, is applied spirally about the form,and means for applying vibration whereby during application of the stripto the form it is caused to embed itself to an intermediate depth in thelayer of plastic material.

'11. In a pipe coating machine, means for supporting and rotating a formto be coated, a hopper adapted to receive a mass of hydraulic plasticmaterial and having a lower discharge opening, means for guiding a stripof formainous reinforcement beneath said opening, whereby concrete fedthru said opening is deposited upon said strip, means for progressingthe hopper and guide means longitudinally of the pipe, whereby the stripof reinforcement together with the layer of plastic material carried bythe same, is wound spirally upon the pipe, means for repeatedly poundingthe coating'as it is applied to the under side of the pipe, and meansoverlying the pipe for repeatedly vibrating the coating, before settingof said plastic material.

12. In a machine of the character described, means for supporting androtating a form to be coated, a framework disposed alongside the formmeans for progressing the framework longitudinally of the axis ofrotation of the form, a guide structure movably carried by the frameworkand normally disposed at an angle to the axis of the form, saidstructure having a substantially flat bottom and having its one endterminating adjacent the lower side of the form, said guide structurebeing adapted to receive a strip of foraminous reinforcement to be woundspirally about the pipe, means for feeding said strip into said guidestructure and for tensioning the same, a hopper carried by the frameabove the guide structure and adapted to receive hydraulic plasticmaterial, said hopper having a lower discharge opening overlying saidguide structure and of a width substantially the same as that of theguide structure, a plate underlying the form" and serving as anextension of said guide structure, and means for feeding a strip ofsurfacing materialover the upper surface of said plate and beneath saidreinforcement.

13. In a. machine of the character described, a guide structure overwhich a layer of hydraulic plastic material may pass to be appliedhelicoidally upon a pipe or like form, a hopper overlying said structureto receive a charge of said material, means for feeding a conveyingstrip beneath said hopper and over said structure, a resilient lipformed upon the'hopper beneath which the plastic material may flow, andmeans for rapidly vibrating said lip.

14; In a method of coating pipes or like forms with concrete, the stepsof applying a layer of the concrete in plastic form' upon a strip offoraminous metal reinforcement, wrapping the strip about the pipe withthe concrete between the outer surface of the pipe and thereinforcement, and applying vibration and tension to the V 3,968,725reinforcement to cause it to embed itself into the layer of concrete.

15. In a method of coating pipes or like forms with concrete. the stepsof applying a layer of the concrete in plastic form upon a strip offoraminous metal reinforcement, wrapping the strip about the pipe withthe concrete between the outer surface of the pipe and the reinforce-'ment, applying vibration and tension to the reinforcement to cause it toembed itself into the layer of concrete, and then smoothing over theconcrete thereby extruded thru the perforations of the reinforcement.

16. In apparatus for coating pipes or like forms, means for wrapping astrip of foraminous metal reinforcement helicoidally about a pipe, meansfor applying a layer of plastic concrete upon one side of thereinforcement whereby the layer is wound upon the pipe together with thereinforcement, means for applying tension and vibration to thereinforcement. to cause it to embed itself into the layer of concrete onthe pipe, and means for smoothing over the concrete thereby extrudedthru the perforations of the reinforcement.

17.. In a method of coating pipes or.like forms with plastic'materiaLthe steps of applying a layer of plastic material upon a stripof foraminous metal reinforcement which is relatively narrow compared tothe length of the pipe, wrapping the strip together with the plasticlayer helicoidally upon the pipe, tensioning the reinforcement andtamping the plastic material together with the reinforcement as it! isapplied to the pipe to cause the reinforcement to embed itself in theplastic material. thereby forming both outer and innerlayer portions ofplastic material on the sides of the reinforcement without furtherapplication of plastic material, and compacting the outer layer portionto-form an uninterrupted covering for the reinforcement;

18. In a process of the character described, the steps of continuouslyforming a layer of plastic concrete from a mass of the same. con-,

tinuously conveying said layer away from the mass and wrapping the sameabout a form, and

"rapidly pounding the layerimmediately upon contacting the same with theform. g 19. In a process of thecharacter described, the steps ofcontinuously forming a layer of plastic concrete from a mass of thesame, continuously conveying said layer away from the mass and wrappingthe' same spirally about a pipe or like form, and continuously vibratingthe layer prior to contacting the same with the.

Pipe.

reinforcement toward the pipe and causing the the steps of rotatfiig apipe or like form to be coated, applying a layer of plastic concretespirally to the pipe in sucha manner as tooverlap successiveconvolutions, land tamping the concrete after application .to produce asubstantially uniform coating.

21. In a method of the character described, advancing a strip offoraminous metal reinforcement toward a pipe or like form and causingthe same to wrap upon the pipe spirally, continually supplying concreteto said strip while the strip is advancing toward the pipe, causing saidconcrete to be distributed to cover both sides of said strip, andutilizing said strip as a conveying medium to carry the concrete uponthe pipe to form a continuous reinforced'coating.

22. In a method of the character. described, the steps of rotating apipe or like form to be coated. advancing a strip of foraminous metalsame to wrap .upon the pipe spirally, continually supplying concrete toone side of said strip while the strip is advancing toward the pipe.causing said concrete to be distributed to cover both sides of saidstrip, and utilizing said strip as a conveying medium to carry theconcrete upon the pipe to form a continuous reinforced coating.

23. In a method of the character described, the steps or rotating a pipeor like form to be coated, continuously advancing a strip of foruminousmetal reinforcement toward the pipe and causing the strip to wrap uponthe pipe spirally, continually delivering plastic concrete to one sideof the strip while the strip is advancing toward the pipe. causing theconcrete to be distributed to cover both sides of the strip. andapplying a-covering strip upon the pipe simultaneously with thereinforcing strip and the concrete carried by the same, said latterstrip being 5 likewise wound spirally and applied on the outer surfaceof the concrete.

24. In a method of the character described.

the steps of rotating a pipe or like form to be taneously withapplication of the reinforcement strip and the concrete, said clothstrip being likewise wound spirally and applied on the 1 outer surfaceof the concrete under tension.

- WARREN A. KRANER.

